Because a Dimers Pro subscription can be purchased on the web (via www.dimers.com), or on the Dimers app via the Apple App or Google Play Stores, your cancellation method depends on where you originally subscribed.

Go to Subscription
Select Manage
Click Cancel subscription
Your access will continue until the end of your current billing period.
Google Play manages your billing, so cancellation must happen through Google Play — not the Dimers website.
You can reach this two ways:
Option A — From the Dimers Pro App
Open the app
Go to My Dimers
Tap Manage Subscription
This will redirect you to your Google Play subscription page
Choose Cancel subscription
Option B — Through Google Play directly
Open the Google Play Store
Tap your profile icon
Go to Payments & subscriptions > Subscriptions
Select Dimers Pro
Tap Cancel subscription
Apple controls billing for all App Store purchases. You must cancel through your Apple ID — Dimers cannot cancel this for you.
Option A — From the Dimers Pro App
Open the app
Go to My Dimers
Tap Manage Subscription
This will open your Apple subscription settings
Select Cancel subscription
Option B — Through Apple Settings
Open Settings on your iPhone
Tap your name
Go to Subscriptions
Select Dimers Pro
Tap Cancel Subscription